from matplotlib import pyplot as plt
import numpy as np

fig,axes=plt.subplots()
x_bar=np.arange(10,60,10)
y_bar=[0.5,0.6,0.3,0.4,0.8]
bars=axes.bar(x_bar,y_bar,color='blue',label=x_bar,width=2)
for i,rect in enumerate(bars):
    x_text=rect.get_x()
    y_text=rect.get_height()+0.01
    plt.text(x_text,y_text,'%.1f'%y_bar[i])
plt.annotate('Min',xy=(32,0.3),xytext=(36,0.3),arrowprops=dict(facecolor='black',width=1,headwidth=7))
plt.show()
